Sprags for one-way clutches



Sept. 18, 1956 FIG.2. A

| T. SZADY 2,763,354

SPRAGS FOR ONE-WAY CLUTCHES Filed April 13, 1953 FIGJ.

I INVENTOR. LEOPOLD T. SZADY WAZ W ATTO RN EYS United States PatentSPRAGS FOR ONE-WAY CLUTCHES Leopold T. Szady, Hamtramck, Mich., assiguorto Formsprag Company, Van Dyke, Mich., a corporation of MichiganApplication April 13, 1953, Serial No. 348,540

3 Claims. (Cl. 192-45.1)

The invention relates to one-way clutches including coaxial driving anddriven rotary members having radially spaced concentric raceways thereonand a series of sprags interposed between said raceways. Thisapplication is a continuation in part of my application Serial No.209,356 for Sprags for One-Way Clutches and Method of Forming the Same,filed February 5, 1951, Patent No. 2,715,262, August 16, 1955, theinstant application being for the construction of sprags. With suchclutch constructions, it is necessary to provide means for energizingthe sprags or turning them so as to frictionally engage the raceways.This is sometimes accomplished by garter springs formed of helicallycoiled resilient wire which surrounds the series of sprags and engageproperly inclined channels or apertures therein so as to impart to eachsprag a torque stress. With certain constructions the garter springreceiving channels are formed in one or both ends of the sprag andusually subsequent to the severing of the sprags from a stock bar andthe heat treatment for hardening the same. However, this requires notonly a distinct mechanical operation but also the orienting of theseparate sprags for feeding to the channel forming means.

It is the object of the instant invention to obtain a construction ofsprag in which the garter spring receiving channels may be made in thestock bar prior to the severing of the sprags therefrom. To this end,the invention consists in the construction as hereinafter set forth.

In the drawings:

Fig. l is a side elevation of a sprag of my improved construction;

Fig. 2 is an end elevation thereof;

Fig. 3 is a plan view illustrating a method of forming the channel inthe stock bar and then severing the bar into individual sprags;

Fig. 4 is a View similar to Fig. 3 illustrating a modified method forforming the channels in the stock bar and for severing the same intoindividual sprags;

Fig. 5 is a side elevation of the construction of sprag illustrated inFig. 4; and

Fig. 6 is an end elevation thereof.

My improved sprag may be varied as to its cross sectional contour but,as specifically illustrated, this contour includes diametricallyopposite eccentric cam portions A and B, a generally radial side Cbetween said cam portions and an opposite side having oppositelyinclined portions D and E extending to a central rounded nose portion F.The sprags may be formed from drawn or extruded stock bars having thecross sectional contour as just described and such bars are severed intosuitable lengths for forming the individual sprags. However, before theseverance of the sprags the bar is chan- 2,763,354 Patented Sept. 18,1956 nelled and the channels are located to be at one or both ends ofthe severed sprags. The channels G- extend transversely across the spragadjacent to one of the cam surfaces thereof and are inclined from theside C to the side portion E. Thus with a series of sprags in assembledrelation to the other elements of the clutch, a garter spring N can beengaged with the channel of the sprag and will bear thereagainst at oneside of the center of turning of the sprag so as to impart a torquestress thereto. This will energize the sprags to turn the cam faces Aand B thereof into frictional engagement with the raceways on thedriving and driven members. To retain the garter spring when onceengaged, the chan nels G are undercut as indicated at H so that theresilient pressure of the spring against such undercut portion will holdit from endwise displacement.

In the method of forming the sprags, as above described, the stock bar Iis advanced longitudinally step by step a distance equal to the lengthof the sprag plus the material removed in the severing of the bar. Thechannels G with their undercut portions H are formed by moving asuitable fashioned rotary cutter J transversely across the bar andthrough a path to give the proper inclination to the channel. The crosssection of the cutter 1 corresponds in contour to the undercut portion Hof the channel. The bar is severed into sprag lengths by a rotary cutterK and if desired this may be coaxial with the cutter I but projectsbeyond the periphery of the latter to extend completely across the bar.It will, of course, be understood that where both operations areperformed simultaneously by cutters I and K on the same arbor it will benecessary to hold the bar from transverse displacement during thisoperation.

Sprags formed by the method above described only require heat treatmentand hardening to complete the same and are then in condition forassembly in the clutch.

With the modified method illustrated in Fig. 4, a rotary cutter orgrinder wheel L is fashioned to form the channels in the bar and thissame cutter is used for severing the bar into individual sprags. Inalternate operations of the cutter L, it is moved laterally differentdistances with respect to the bar M and intermediate each operation saidbar is advanced an amount substantially equal to one-half the spraglength. Thus in one operation of the cutter L, it is moved to form achannel G in the sprag and in the alternate operation it is movedcompletely across the bar ot sever the sprag therefrom. As theadvancement of the bar is between each operation of the cutter, thechannel will be located centrally between the ends of the severed sprag.

One of the important advantages of the construction of sprag as abovedescribed is that it is capable of being formed by the method describedwhich latter forms the subject matter of my application, Serial No.209,356, Patent No. 2,715,262, August 16, 1955. In addition to this, theconstruction in both of its modifications respectively illustrated inFig. 1 and Fig. 5 has the channels for receiving the energizing garterspring formed in one of the cam faces of the sprag. Thus the garterspring may be engaged with the series of sprags peripherally in theconstruction of Fig. 5 or either peripherally or endwise in theconstruction shown in Fig. 1.

What I claim as my invention is:

1. A sprag for one-way clutches having diametrically opposite eccentriccam faces, one of said faces having a transversely extending channeltherein open radially out- References Cited in, the file of this patentUNITED STATES PATENTS. [2,364,280 Dodge Dec. 5, 1944 10 4 Dodge Sept.17, 1946 Davis Oct. 25, 1949 Turner Oct. 9, 1951 Turner June 3, 1952FOREIGN PATENTS Australia Sept. 6, 1949

